Insulating shield and mounting device for color television tubes



1958 R. A. FISCH INSULATING SHIELDNAND MOUNTING DEVICE FOR COLOR TELEVISION TUBES Filed July 11, 1955 IN VEN TOR. E/CH/l/PO I). F/SCA Arr-0e 4/575 United States Patent INSULATING SHIELD AND MOUNTING DEVICE FOR COLOR TELEVISION TUBES Richard A. Fisch, Forest Hills Gardens, N. Y. Application July 11, 1955, Serial No. 521,175 3 Claims. (Cl. 340-367) This invention relates to an insulating and mounting device for metal backed cathode ray tubes employed in color television.

Among the objects of the invention is to provide an insulating and mounting device for color television picture tubes in which the parts thereof cooperate to provide an interlocking structure.

Among other objects of the invention is to provide a plural part insulating shield for metal backed color television tubes of the type having a peripheral projecting flange adjacent the larger part of the metal backing part Of the tube in which portions of the insulating shield parts overlap to provide for the complete insulation of the tube.

These objects and others ancillary thereto are obtained by providing an insulation device comprising a gapped ring member adapted to fit around the end portion and overlap at the open ends of the gapped ring, and a cone member adapted to fit around the conical part of the tube and extend up to and beyond the rear edge of the gapped ring. The cone member comprises an offset portion at the larger end thereof adapted to overlap the lower edge of the gapped ring including the overlapped ends of the latter whereby the cone member holds the gapped ring in place on the tube. In addition, interlocking beads may be formed on the interior of the olfset portion of the cone member or on the exterior of that portion of the ring which is overlapped by the cone member. An additional insulating ring may be provided to fit into the portion of the tube between the flange and the lens and provide a support for a strap, holding magnets, which is placed around the color TV tube.

The invention both as to its organization and its method of operation together with additional objects and advantages thereof will best be understood from the following'description of specific embodiments thereof when read in connection with the accompanying drawing in which Fig. 1 is a side view of a color television tube with the insulating device of the invention applied thereto.

Fig. 2 is a detail view of the insulating ring.

Fig. 3 is a cross-sectional detail view of the insulating ring, taken on line 33 of Fig. 1, with the magnet ring added.

Fig. 4 is a side view, partly in cross section, of a modified form of the cone member.

Fig. 5 is a side view of a tube mounted with the aid of the ring and cone member of the invention.

The color television tube comprises a metal backing member 11 of generally frustoconical shape with a peripheral flange 12 extending around the larger end adjacent to but spaced from the edge 13 of the larger end. The edge 13 is also flanged to provide a seat for the glass lens 14. Between flange 12 and edge 13 is a flat depressed area 15. These are the general characteristic parts of a color TV tube although the various dimensions of the parts may vary widely.

2,866,187 Patented Dec. 23, 1958 The insulating shield of the invention comprises two or three parts, the ring member 20, the cone member 30 and the magnet insulator 40. The ring member 20 is gapped or open so that it can be wrapped around the large end of the metal backing section 11. An overlap of at least 6 inches at the gapped ends 21 and 22 of the ring is provided. The ring has an internal flange 23 at the edge thereof adapted to lock onto the edge 14 of the metal backing member 11 and a grooved portion 24 adapted to fit about the flange 12 of the tube 10. Between grooved portion 24 and interior flange 23 of the ring is the flat portion 25 adapted to fit snugly into the similar flat portion 15 of the tube 10.

The rear apron portion 26 of ring 20 includes a head 27 extending at least part of the distance around the said apron 26. This bead 27 may have an almost vertical front wall (as shown in Fig. 3) to provide an interlocking engagement with a similar bead 37 on the cone member 30.

The cone member 30 is formed to fit snugly about the smaller conical end portion of the tube. Thus this cone member 30 has (a) a small tubular portion 31 for fitting about the corresponding section of tube 10, (b) an enlarged portion 32 fitting about the glass bulb section of tube 10, (c) a frusto conical portion 33 for fitting about the metal backing 11 and (d) an edge section 34 which is slightly offset outwardly from the section 33 so as to. overlap the lower edge portion of ring 20 and especially to overlap and hold in place the overlapped ends of the said ring 20. The portion 34 also includes an interior bead 37 which is adapted to interlock with bead 27 on the ring 20. In this way the cone member 30 locks the ring 20 in position about the end of tube 10. These parts actually fit rather tightly together although for clarity the various overlapping portions are shown in spaced relationship. Thus the bead member 27 of the ring 20 serves also to hold the cone member 30 in place on the tube 10.

The part 40 is a second ring member made of insulating material. This ring member 40 has the flat central portion 41 and the two outwardly extending flanges 42 and 43. The flat portion 41 is adapted to receive the straps 43, on which magnets 51 are mounted by means of a bridge 50 which comprises the hollow or channel housing 52. The magnets 51 (only one shown) are adjustably held in position by wing nuts 53. Since the parts 51 to 54 are metallic it is necessary to avoid any leakage from the metal back 11 of tube 10 to the said coil 50. The necessary extended creepage path is provided by the flanges 42 and 43. The flange 42 is short enough so as not to interfere with the mounting of the tube in a cabinet, for example, but in order to assure a long creepage path of at least 5 inches, a plurality of smaller flanges 45 are formed thereon. I

In practice the gapped ring 20 it fitted about the flanges 12 and 13 of the tube 10 and the cone portion 30 is. applied with the edge portion 34 overlapping the inner edge 26 of the ring 20 and the head 37 is snapped over the bead 27. The insulating ring 40 is then applied and the coil 50 is fitted in place. The tube is then ready for mounting on the chassis of a color TV set.

In order to provide for accurate mounting of the tube in the chassis 50 of a television set the additional bead 38 on the outside of the cone member 30 may be provided as shown in Figs. 4 and 5. This bead 38 is formed on the cone member 30 along a line which corresponds to the position of a yoke member 61 in chassis 60.

The features and principles underlying the invention described above in connection with specific exemplifications will suggest to those skilled in the art many other modificat ons thereo i a or n y e ire ha h appended claims shall not be limited to any specific feature or details thereof.

This application is a continuation-in-part of U. S. application Serial No. 481,620, filed January 13, 1955.

We claim:

1 A plural part insulating shield for a metal-backed color cathode ray tube of the type having an outwardly projecting flange adjacent the lens end thereof, comprising a first overlapping gapped ring member having an internal peripheral groove adapted to extend over the said flange of the cathode ray tube, the interior edge portion of said ring extending beyond said flange and over a substantial portion of the metal backed area of the tube, said first gapped ring having an interior flange on the front edge portion adapted to extend over the corresponding front edge portion of the cathode ray tube adjacent the lens thereof and an exterior bead extending along "the interior edge portion thereof, and in combination therewith a conical insulating member adapted to extend from the glass portion of the cathode ray tube substantially up to the flange of the latter, said conical portion fitting snugly about said tube and including an interior bead adjacent the edge portion of the larger end thereof adapted to interlock with the exterior bead of the first gapped ring member whereby the said parts cooperate to completely cover all metal portions of the cathode ray tube and to lock each other in position.

2. The device as set forth in ,claim 1 cornprisingtin addition a second ring member adapted to fit outside of the first gapped ring member in the area between the peripheral groove and the interior flange of said first gapped ring member, said second ring member having an exteriorly extending peripheral flange portion at each side thereof whereby to provide an extended creepage path of at least 5 inches between the metal portion of said tube'and a metal coil extending around said second member. i v

3. The device as set forth in claim 1 comprising an exterior bead on the outside of the conical member having .a substantially vertical rear wall adapted to position the tube enclosed by the conical member with respect to a support on the chassis of a TV set.

References Cited in the file of this patent UNITED STATES PATENTS 2,560,336 Fisch July '10, 195] 2,654,880 Eisenkramer Oct. 6, 1953 2,70 ,065 Stone Apr. 12, 1955 2,753,991 Sherman July 10, 1956 OTHER REFERENCES RCA Service Data, March 3, 1954, pp. 6 and 10., 

